Former U.S. National Security Agency contractor Edward Snowden said on Wednesday that he was leading an ordinary life in Moscow, where he has lived for over a year.

Snowden caused an international uproar in 2013 when he disclosed details of the extent of surveillance and electronic monitoring by the NSA and its British equivalent, the General Communications Headquarters.

He was offered a temporary asylum in Moscow and later a three-year residency permit.

“I'm doing quite well; I live an ordinary life. I ride the Moscow underground like everybody else. The only difference between my life before and now is, obviously, that I'm not living in my home. I'm not able to return,” Snowden said, addressing a conference in Paris from Moscow.

The conference on data surveillance was organized by rights group Amnesty International.

The former NSA contractor said mass surveillance had never helped in preventing terrorist acts.

“Every time that those programs have been reviewed, we have found that in fact they never stopped a single imminent terrorist attack,'' he said.

Snowden said he no longer had any access to U.S. classified information.

“I destroyed my own access when I went to Hong Kong. Everything had been provided to the journalists. So I can't break news. That's the role of the press, that's not the role of myself as a whistleblower,” he said.